Understanding, and inspiration. They had to create under serious constraints in compute, memory, and storage, and understanding how and why they did can lead to ideas about how to optimize software on modern machines.
It's also critical for understanding how and why the engineering choices were made when documenting the evolution of processing. Instruction sets, processor design, programming languages, computer culture, corporate trends, all of those things have roots in design decisions, and the software preserved on tapes like this are a sort of DNA.
The effort needed to incorporate the information is dropping, with AI you can run analysis and grab important principles and so on, and whatever principles govern optimization and performance under constraints will be useful on a permanent basis.
You never know what will be important to people in the future.
I just listened to a great new episode (podcast) of The Truth (audio drama anthology series, they’re fantastic). It was called “The Joke.” Basically this archivist finds an old hard drive with a dumb pun joke - turns out she didn’t even understand it because jokes were no longer allowed in society. Kind of has an Equilibrium vibe but more bureaucratic and less “killing people for feeling.” Anyway the joke itself takes on great importance as a result. Bit of a dramatic comparison, but you see what I’m driving at.
On one side I think we need to preserve this relic as we did with Homer's poetry. Because it just deserves.
On another side I think we won't (and should not) try to preserve in an infinite present whatever has been written by humanity. For what purpose?